In recent years, in order to improve performance of various safety devices such as a seat belt or an air bag which is equipped in an automobile, there are cases where operation of the safety devices is controlled in accordance with the weight of the occupant who is seated on a seat. For example, in North America, there is a problem in that harm is caused to a child who is seated in a child seat due to an impact during deployment of the air bag in a child seat fastened state such that the child seat is fastened oriented to the rear on the front passenger seat. Thereby, in the child seat fastened state such that the child seat is fastened oriented to the rear on the front passenger seat, it is determined that deployment of the air bag is prohibited. In this manner, correctly determining a seat load by detecting the load which acts on the seat is extremely important.
As the related art, there is a child seat detection device or a child seat detection method described in JP 2007-76598A (Reference 1). Reference 1 discloses that a plurality of load sensors that are provided in a vehicle seat are provided in the child seat detection device which detects whether the child seat is mounted on the vehicle seat, in which when the child seat is fixed, the closest load sensor to an anchor of the seat belt on which a large load acts is set as a specific sensor, and it is determined whether the child seat is mounted using a load value which is detected by a load sensor that does not include the specific sensor.
According to the child seat detection device or the child seat detection method, it is possible to detect with high precision whether the child seat is mounted using the detection value of the load sensor other than the specific sensor on which the large load acts.
In addition, in an air bag system of a vehicle described in JP 10-194080A (Reference 2), it is disclosed that in a case where the door is detected to be in a closed state, the current control state is held.
According to the air bag system of a vehicle, it is possible to prevent improper performance of switching of necessity for air bag deployment within the door closed state under the premise that there is little change of presence or absence of an occupant and presence or absence, orientation, and the like of a child seat which is mounted on a seat within the door closed state.
However, when a child seat is mounted on a vehicle seat, there are times when the mounter of the child seat rests on a seat cushion. In this case, a load of the mounter is applied on a load detection device which is installed on a lower side of the vehicle seat, and the load which is detected by the load detection device increases. When the load which is detected by the load detection device increases, there are times when an occupant discrimination portion discriminates that there is an adult regardless of the child seat being mounted.
In such a case, in the child seat detection device or the child seat detection method described in Reference 1, there is a concern that it is determined that an adult is seated regardless of the child seat resting on a vehicle seat since the detected load of the load sensor other than a specified sensor increases.
In addition, in Reference 2, in the case of the door open state, there is a concern that when the detected load of the load sensor increases due to the mounting of the child seat since a control state is not maintained, it is determined that an adult is seated on the seat.